Gustavo on Software Development

This is the March-April 2012 issue of The Software Practitioner’s Digest, featuring an experimental format where the editor’s comments are presented in an introductory video and the highlighted publications are listed with their original abstracts.

In this issue:

• Mutation-Driven Generation of Unit Tests and Oracles
• Easy Approach to Requirements Syntax (EARS)
• Comparison of approaches to improve user interface design

Mutation-Driven Generation of Unit Tests and Oracles

Mutation-Driven Generation of Unit Tests and Oracles, IEEE Transactions on Software Engineering, March-April 2012.

To assess the quality of test suites, mutation analysis seeds artificial defects (mutations) into programs; a nondetected mutation indicates a weakness in the test suite. We present an automated approach to generate unit tests that detect these mutations for object-oriented classes. This has two advantages: First, the resulting test suite is optimized toward finding defects modeled by mutation operators rather than covering code. Second, the state change caused by mutations induces oracles that precisely detect the mutants. Evaluated on 10 open source libraries, our μtest prototype generates test suites that find significantly more seeded defects than the original manually written test suites.

Related reading

• Mutation testing.
• Test oracle.

Easy Approach to Requirements Syntax (EARS)

Listen, Then Use EARS, IEEE Software, March-April 2012.

Applying the Easy Approach to Requirements Syntax (EARS) template can result in a simple, clear requirement. However, to be able to write a simple statement, you must first understand what you want the system to do, which might be difficult. The simplicity of the EARS templates prevents engineers from hiding behind ambiguous statements of what the system must do.

Related reading

• Easy Approach to Requirements Syntax (EARS), 17th IEEE International Requirements Engineering Conference.
• User stories, an alternative approach which is commonly used by Agile teams, which could actually be complemented by EARS .

Comparison of approaches to improve user interface design

A/B Testing, Usability Engineering, Radical Innovation: What Pays Best?, Jakob Nielsen’s Alertbox.

3 approaches to better design: each has its uses, but the costs, benefits, and risks differ dramatically.

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Due to the low volume of relevant resources published during even months, I’ve decided to make The Software Practitioner’s Digest a bimonthly periodical starting with the March/April 2012 issue to be published in early May.
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This late issue of The Software Practitioner’s Digest, the first in 2012, highlights resources published in January in Better Software, Dr. Dobb’s, IEEE Software and Software Engineering Radio.

This digest has been the most difficult to compile so far, given how hesitant I was with regards to the inclusion of some research articles and essays which — although very revealing or thought-provoking — did not have much (or any) actionable material for practitioners. I decided not to include them in this issue, but I’d like to know whether my modest readership would enjoy finding articles that are simply interesting in future issues (rest assured that these would be backed by some evidence!). Please let me know what you think!

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This is the third issue of the The Software Practitioner’s Digest, covering the little activity from December 2011 — A very quiet month not only because of the holiday season, but also because it’s an even month and the periodicals I follow are published in odd months. The next issue should be along the lines of the October and November issues, so stay tuned!

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This tardy issue of The Software Practitioner’s Digest highlights articles from Better Software, IEEE Software, Software Engineering Notes and Jakob Nielsen, as well as a book on applied psychology in software development teams, all of which were published in November 2011.

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Hello, World! You’re reading the first issue of The Software Practitioner’s Digest, covering resources published during October 2011. Continue Reading »

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I’ve just uploaded the materials for my tutorial at EuroPython 2010, “WSGI from Start to Finish”. You can also get the slides and the WSGI cheat-sheet individually. I’ve updated the slides so that they make sense even without me speaking; so now they have references to the code examples.

The tutorial was recorded and should be published on the EuroPython Web site after the event.

This was the first time I give such a long talk. Three hours talking about WSGI! But it was really fun. And the room was absolutely full, which I couldn’t believe.

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This article first appeared in the May 2009 issue of Python Magazine and has been slightly updated. The contents of the article are only applicable to repoze.who 1.0 and repoze.what 1.0, not repoze.who 2 and repoze.what 1.1 which are under development as of this writing.

Have you ever created a Web application? If so, it’s very likely that you have at one time or another faced “the security problem”; whether to create and maintain a homegrown security sub-system, or to learn to use framework-specific security mechanisms (which may not be as flexible as you wish).

Securing Web applications shouldn’t be a problem. This article explores a highly extensible alternative which you can learn once and use in arbitrary applications, regardless of the Web framework used (if any!).
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If you’re a Web Application Developer using Python, you may be very interested in the tutorial I am presenting at EuroPython 2010: “WSGI from Start to Finish: How to use the power of WSGI to solve problems your framework cannot solve”.

Your favorite Web framework is not able to meet all your needs, all the time; some problems cannot even be solved at the framework level. In such situations, the Python Web Server Gateway Interface may save you a lot of time and trouble, giving you the opportunity to implement an elegant solution or integrate existing framework-independent third party solutions.

And chances are, a better WSGI-based alternative exists for something your framework is apparently good at. WSGI is a very powerful technology, and the kind of things you can do with it may surprise you.

It doesn’t matter if you know little about WSGI or nothing at all, because when I say “from start to finish” I really mean it. In this half-day tutorial, I’ll try to cover both simple and complex real-world situations solved with WSGI. The tutorial is relevant for Django/Pylons/TurboGears/etc users, and for those who don’t use a Web framework at all!

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A few weeks ago I started the Repoze and WSGI groups on identi.ca. Please feel free to join us if you have something to share! Or just keep an eye on those groups to receive updates.